Fix inputCoverageIsUsed bug in GrGLProgramDesc

src/gpu/gl/GrGLProgramDesc.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gl/builders/GrGLProgramBuilder.h"
 #include "GrGLProgramDesc.h"
 #include "GrBackendEffectFactory.h"
@@ skipping 155 matching lines @@
                             GrGpuGL* gpu,
                             const GrDeviceCoordTexture* dstCopy,
                             const GrEffectStage** geometryProcessor,
                             SkTArray<const GrEffectStage*, true>* colorStages,
                             SkTArray<const GrEffectStage*, true>* coverageStages,
                             GrGLProgramDesc* desc) {
     colorStages->reset();
     coverageStages->reset();
 
     bool inputColorIsUsed = optState.inputColorIsUsed();
-    bool inputCoverageIsUsed = optState.inputColorIsUsed();
+    bool inputCoverageIsUsed = optState.inputCoverageIsUsed();
 
     // The descriptor is used as a cache key. Thus when a field of the
     // descriptor will not affect program generation (because of the attribute
     // bindings in use or other descriptor field settings) it should be set
     // to a canonical value to avoid duplicate programs with different keys.
 
     bool requiresColorAttrib = optState.hasColorVertexAttribute();
     bool requiresCoverageAttrib = optState.hasCoverageVertexAttribute();
     bool requiresLocalCoordAttrib = optState.requiresLocalCoordAttrib();
 
@@ skipping 182 matching lines @@
     *checksum = 0;
     *checksum = SkChecksum::Compute(reinterpret_cast<uint32_t*>(fKey.begin()), keyLength);
 }
 
 GrGLProgramDesc& GrGLProgramDesc::operator= (const GrGLProgramDesc& other) {
     size_t keyLength = other.keyLength();
     fKey.reset(keyLength);
     memcpy(fKey.begin(), other.fKey.begin(), keyLength);
     return *this;
 }